Spurious #DB exceptions with the "MOV SS" and "POP SS" instructions (CVE-2018-8897)
https://www.triplefault.io/2018/05/spurious-db-exceptions-with-pop-ss.html [www.triplefault.io]
2018-05-10 15:27
If the instruction following the MOV SS or POP SS instruction is an instruction like SYSCALL, SYSENTER, INT 3, etc. that transfers control to the operating system at CPL < 3, the debug exception is delivered after the transfer to CPL < 3 is complete. OS kernels may not expect this order of events and may therefore experience unexpected behavior when it occurs.
source: L